COPD, Healthy Adult
Conditions
Keywords
Shear wave elastography, Intercostal muscles, work of breathing
Brief summary
Quantifying respiratory effort is a key step in physiological and clinical research on exercise tolerance, mechanisms of fatigability, and ventilatory impairment. To date, reliable assessment relies on an invasive method: esophageal pressure (Pes) measurement using a balloon catheter inserted into the esophagus. Although Pes provides an indirect estimate of pleural and intrathoracic pressure, it is uncomfortable for patients, requires dedicated equipment, and may limit study participation. In critically ill patients, a noninvasive approach to quantify respiratory effort would have major clinical and scientific value. In acute respiratory distress, accurately tracking the intensity and evolution of respiratory effort could support earlier therapeutic decision-making. Shear Wave Elastography (SWE) is an ultrasound technology enabling very high acquisition rates and estimating tissue stiffness from shear-wave propagation induced by an acoustic impulse. Because muscle stiffness is strongly related to force produced during contraction, we hypothesize that intercostal muscle stiffness measured by SWE correlates with respiratory work and increases with rising inspiratory load.
Interventions
DIAGNOSTIC_TESTIntercostal muscle shear wave elastography (SWE) during standardized inspiratory loading
Ultrasound shear wave elastography (SWE) is performed to quantify intercostal muscle stiffness at rest and during standardized inspiratory loading/controlled breathing. SWE acquisitions are synchronized with physiological reference recordings (e.g., esophageal pressure and/or diaphragm EMG when available) to estimate and track respiratory effort/work noninvasively.
Sponsors
Groupe Hospitalier du Havre
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Adult patient with chronic obstructive pulmonary disease (COPD), stage 3-4. Healthy adult volunteer.
Exclusion criteria
Refusal to participate or withdrawal of consent. Age \< 18 years. BMI \> 35 kg/m². Pregnancy or breastfeeding. Inability to understand instructions or cooperate (cognitive impairment, language barrier). Neurological condition affecting breathing (e.g., recent stroke, ALS, myopathy). Thoracic condition limiting access to the intercostal muscles (e.g., major chest wall deformity, surgical scar). Recent thoracic or abdominal surgery (\< 3 months). Known esophageal disease (stricture, achalasia, severe esophagitis, diverticulum, history of perforation). ENT or tracheal abnormality preventing probe insertion (e.g., tumor, malformation, tracheostomy). Swallowing disorders or risk of aspiration. Recent exacerbation (\< 6 weeks). Oxygen therapy \> 2 L/min during exertion. Hemodynamic instability. Not affiliated with a social security scheme. Legally protected persons (as defined by law).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Correlation between intercostal muscle stiffness (SWE) and respiratory effort (esophageal pressure-time product) | During a single study visit (≈45 minutes), at rest and at each standardized inspiratory load level | Intercostal muscle stiffness (kPa) measured by shear wave elastography is correlated with respiratory effort quantified by the esophageal pressure-time product (PTPes; cmH2O·s/min) across the standardized inspiratory loading protocol (within each cohort). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Within-subject change in intercostal muscle stiffness (SWE) across inspiratory load levels | Single study visit: during the inspiratory loading protocol (no resistance, then 25%, 50%, and 75% of maximal inspiratory pressure [PiMax]) | Intercostal muscle stiffness (kPa) measured by shear wave elastography (SWE) will be assessed within participants across the different inspiratory load levels. |
Contacts
CONTACTClément Medrinal
CONTACTAngélique Picard
Outcome results
None listed